BMN 390 fell short of an immunogenicity threshold that BioMarin was looking for to support its further development. Employees working on the program have been redeployed within the company.
BioMarin will no longer develop BMN 390, a pre-clinical candidate it was developing for phenylketonuria.
BMN 390 “did not meet its target immunogenicity threshold for advancement,” the biotech wrote in a news release on Tuesday announcing its second-quarter earnings results. Employees who were working on BMN 390 “have been redeployed” to other roles within the company, according to the statement.
BioMarin had been hoping to position BMN 390 as a successor to its current phenylketonuria (PKU) therapy Palynziq, chief R&D officer Gregory Friberg told Fierce Biotech in February. According to a September 2024 news release, the company had tweaked Palynziq’s structure to produce BMN 390, with a lower risk of anaphylaxis than Palynziq. Those tweaks also produced lower immunogenicity. A month later, the biotech additionally noted that BMN 390 could potentially improve drug exposure while simultaneously lowering hypersensitivity.
BioMarin was originally planning to file an Investigational New Drug application for the asset in the latter half of this year.
Despite dropping BMN 390, BioMarin reiterated Tuesday that it “remains committed” to PKU, though beyond Palynziq, which is currently in late-stage development for use in patients aged 12 to 17, the biotech has no other clinical-stage assets for the indication.
Meanwhile, BioMarin is facing new competition in the PKU space with PTC Therapeutics’ Sephience receiving FDA approval last week. Indicated for adults and children, Sephience won a broad label from the regulator, which signed off on the drug’s use to address hyperphenylalaninemia, a condition related to PKU, in patients as young as 1 month. Phase III data showed that patients treated with Sephience saw a 63% reduction in phenylalanine levels.
Dropping BMN 390 adds worry to BioMarin’s PKU business, Truist analysts wrote in an investor note Tuesday morning. “With termination of BMN390, future of BMRN’s PKU franchise look a bit murky, especially with the imminent launch of Sephience in the U.S,” they said.
"[The] imminent launch of Sephience could pressure Palynziq going forward,” the analysts added.
BioMarin released its second-quarter earnings report on Tuesday, recording $825 million in revenues, a 17% year-on-year growth, and coming comfortably ahead of the consensus estimate of $760 million. The Q2 beat was driven by “stronger than expected” sales from the biotech’s enzyme products, William Blair analysts said in a Tuesday note to investors.
In particular, the achondroplasia therapy Voxzogo surged 20% year-on-year to bring in $221 million in Q2, pointing to its “strong global expansion,” according to William Blair. Vimizim, indicated for mucopolysaccharidosis type IVA, was also a strong contributor to BioMarin’s topline beat with a 21% year-on-year growth to bring in $215 million in sales.
Palynziq made $106 million in the quarter, a 20% increase from the same period last year.
